This course is about measuring shapes. It begins with units of length and area and why square units grow so fast. It then finds perimeters of rectangles, squares and polygons, with fencing costs, and areas of rectangles and squares, with tiles and paths round a garden. Cutting and rearranging shapes gives the area formulas for parallelograms, triangles, trapeziums and rhombuses. The number pi leads to the circumference and area of a circle, with wheels, rings and semicircles. The course ends with the volume and surface area of cubes and cuboids. Each lesson has worked examples and practice with answers.
Primary Years
Mensuration (Level 1)
Units of length, area and volume, perimeter, the areas of rectangles, triangles, parallelograms, trapeziums, rhombuses and circles, and the volume and surface area of cubes and cuboids.
- 7 lessons
Overview
Lessons
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Units of length and area
Millimetres to kilometres, square units, hectares, and why 1 m² is 10,000 cm² and not 100 cm².
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Perimeter
Perimeter of rectangles, squares, triangles and regular polygons, finding a missing side, bending wires, and the cost of fencing.
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Area of rectangles and squares
Area as length times breadth, working back to a side, tiles and carpets, and paths outside, inside and across a garden.
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Area of parallelograms and triangles
Base and height, a parallelogram rearranged into a rectangle, a triangle as half a parallelogram, and right-angled triangles.
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Area of trapeziums and rhombuses
Trapeziums and rhombuses cut into triangles, half the product of the diagonals, and any quadrilateral from a diagonal.
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Circumference and area of a circle
The number π, circumference 2πr, area πr², semicircles, rings, and how far a wheel rolls.
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Cubes and cuboids
Faces, edges and vertices, volume and capacity in cm³ and litres, surface area and the area of four walls.